Labor (2) Research (2) Preschool teachers (2) Mental retardation (2) Elementary school teachers (2) Profesores de enseñanza primaria (2) Profesores de enseñanza preescolar (2) Estudio (2) Deficiencia mental (2) Información (2) Investigación (2) Trabajo (2) nécessité (2) Belize (1) Cuba (1) Valuation (1) Teachers (1) School children (1) Right to education (1) Quality of products (1) Nature study (1) Methodology (1) Letters (1) Learning, Psychology of (1) Id (Psychology) (1) Education (1) Concepts (1) Attention (1) Altars (1) Valoración (1)